Islam is the official religion in Morocco, but it exists in perfect co-existence with the other religions (freedom to practise other religions of revelation is guaranteed by the constitution).
Each day is marked by five calls to prayer. The "Muezzin" announces them from the top of his minaret. During the month of Ramadan, the Moroccans fast, refraining from eating and smoking from sunrise to sunset.
Obviously this disturbs daily life. Most Civil Service and public offices, monuments, museum and shops alter their opening hours. However, non Muslims will always find something to eat in restaurants which stay open. The days may seem long, but the nights are wonderful!